Microsoft has won an appeal against a $388m (£264m) fine handed out in a patent infringement case against software developer Uniloc.
Microsoft was found guilty in April of infringing on Uniloc software patents which covered the securing of applications against software being installed on multiple PCs.
The case ran on for more than six years, and involved one of the largest settlements ever against a firm in software legislative history.
However, a judge today overruled the verdict and cleared Microsoft of any wrongdoing, saying that the jury did not understand the case.
"The court has reviewed the transcripts and evidence with painstaking detail in the light most favourable to Uniloc, careful not to act as the eleventh juror," the judge wrote in his ruling.
"What remains is a firm belief (indeed a certitude) that the jury 'lacked a grasp of the issues before it' and reached a finding without a legally sufficient basis."
Uniloc has already said that it will appeal against the new ruling, and the case is expected to continue for some time unless the participants can agree to settle out of court.
"We are pleased that the court has vacated the jury verdict and entered judgement in favour of Microsoft," said Microsoft spokesman Kevin Kutz in a statement.
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